<?php


$username =$_REQUEST["username"];

$mysql =new mysqli("localhost","root","","pengdandan");

$sql = "SELECT * FROM heibing WHERE username ='$username'";
$result =$mysql->query($sql);


if ($result->num_rows) {
  echo "账号已被注册，请重新输入";

}else {
  echo "你输入的账号可以用";
}

















 ?>
